/* 表格 */
#div3{
    position:absolute;
    width: 340px;
    height: 340px;
    background-color:rgba(180, 180, 180, 0.5);
    position: fixed;

    left:50%;
    top:50%;
    margin-left: -170px;   
    margin-top: -150px;
}
/* 返回 */
#div2{
    position: fixed;
    left:50%;
    top:50%;
    margin-left: -150px;
    margin-top: 85px;
}
/* 注册 */
#div4{
    position: fixed;
    left:50%;
    top:50%;
    margin-left: 10px;
    margin-top: 85px;
}
body{
    background-color:rgb(198, 226, 198);
}